ENGLEWOOD, Colo. -- Chris Harris Jr., the tape review shows, had just one substandard game this season, and it was against New England. In that late-November Broncos loss, Harris, Denver's best cover cornerback, frequently drew the unenviable matchup with Patriots tight end Rob Gronkowski. Gronkowski caught seven passes for 90 yards and a touchdown that day, giving the NFL a fleeting glimpse of what the Pats' offense looked like at full strength.

Pats coach Bill Belichick's facility for dealing with injuries -- he covets versatile players, and those who have played for him have said he cultivates and develops backups as if he is managing a farm team while also coaching the big-league squad -- has been tested this season by an avalanche of loss. It began when Wes Welker left in free agency and Aaron Hernandez was arrested, and it continued even into last week, when linebacker Brandon Spikes was placed on injured reserve just before the Patriots beat the Colts in the divisional round of the playoffs. It is why the opponent the Broncos will face on Sunday looks more like a vintage Patriots team -- circa 2001, featuring a power running attack -- than the more recent pass-reliant incarnations or even, remarkably, the opponent Denver lost to less than two months ago.

This is a "through the looking glass" moment for the Patriots, who are one game away from making their sixth trip to the Super Bowl in the Tom Brady era while largely taking the ball out of Brady's hands. In that Week 12 victory over the Broncos, Brady completed 34 of his 50 pass attempts for 344 yards and three touchdowns. Against the Colts on Saturday? Brady completed just 13 passes, and all six New England touchdowns came on the ground. In fact, the Patriots rushed for 234 yards, completing a two-game stretch in which they ran an astonishing 63 percent of the time.

The Broncos' injuries have been less heralded but no less trying -- left tackle Ryan Clady, defensive tackle Kevin Vickerson, cornerback Champ Bailey and linebacker Von Miller have missed significant chunks of the season (Miller was suspended for the first six games, then was lost with a torn ACL in late December). Harris going down, though, feels like a tipping point -- and could present a temptation for the Patriots.

Harris played more defensive snaps than any other Broncos player in the regular season, and his versatility -- he could play on either side, outside or in the slot -- gave Denver tremendous flexibility in how to deploy others. For instance, Bailey, limited by a foot injury, had worked mostly in the slot; he is now one of the candidates to move outside to replace Harris.

Harris' importance to the Broncos was obvious from the moment he was lost midway through the third quarter on Sunday. Suddenly -- and not coincidentally -- San Diego's Philip Rivers began throwing and connecting, targeting Harris' replacement, Quentin Jammer, who admitted later that mental mistakes led to his poor play. The Chargers scored 17 fourth-quarter points, including two touchdown passes to Keenan Allen.

"It was obvious," Broncos safety Mike Adams said. "When Chris went down, things started to unravel a little bit on the back end. Jam -- I'm not worried about him. He gave up a big play, but he could bounce back. He's been in the league a long time. We've all had bad games before, and we've all slipped up and done something to give up something before. He always bounces back. So I'm not worried about that. It's just little things, little technique things that he can fix. He hadn't been getting reps all week -- and to step into that role is huge. Jam, I'm not worried about at all."

Whatever the Broncos decide to do about covering for Harris' loss, the Patriots will have a decision of their own to make. Do they have enough confidence in their receivers to revive their aerial attack against an anemic pass defense that has, in less than a month, lost its best pass rusher in Miller and its best coverage man in Harris? Or do they stick with a running game that has worked well for a month -- but which simply might not be able to produce enough points to stay with the Broncos' offense?

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In a more routine season, that question would be laughable. After all, Brady and Peyton Manning are largely responsible for cementing this as the most pass-intensive era in the history of football. This is true in terms of both their play and the rule changes that were enacted because of their styles, like the prohibition on defensive players lunging at a quarterback's legs (after Brady suffered a season-ending knee injury) and the emphasis on penalizing downfield contact against receivers (after Patriots defenders mauled Colts receivers in the first AFC Championship Game between Manning and Brady).

There has been nothing routine about this season, though, for the Broncos or the Patriots. Except for the 15th renewal of one of football's most enduring rivalries, and except for how often the players around them have responded to the NFL's most time-worn cliché: next man up.